Safety indwelling needle

ABSTRACT

The mechanism includes: an urging means for urging an inner needle ( 12 ) to the side opposite to an outer needle ( 11 ) with respect to the axial direction of a holder sleeve ( 1 ) for holding the inner needle ( 12 ); an actuator ( 6 ) which is positioned between the urging means ( 8 ) and inner needle ( 12 ), moves together with the inner needle ( 12 ) and has a puncture position retainer for keeping the inner needle ( 12 ) and outer needle ( 11 ) ready for puncture and an inner needle retraction actuating portion for allowing for the retraction actuation of the inner needle ( 12 ); and a slit ( 2 ) for assuring the path of movement of the actuator ( 6 ). The puncture position retainer has a puncture position engagement portion whereby the actuator ( 6 ) is engaged with the holder sleeve ( 1 ) at a position on the outer needle side ( 11 ). The inner needle retraction actuating portion includes: an actuating portion ( 6   a ) for releasing the actuator ( 6 ) from the engaged state of the puncture position engagement portion into the urged state by the urging means ( 8 ) and an actuator housing for enclosing the actuator after retraction of the inner needle.

TECHNICAL FIELD

The present invention relates to a technology of a safety indwellingneedle comprised of an inner needle which penetrates the skin andreaches a blood vessel and a soft outer needle which is located outsideof the inner needle and is to be placed within the blood vessel.

BACKGROUND ART

As a known method for infusing a medical fluid or the like into apatient, an outer needle (catheter) is inserted and placed in the humanbody to infuse the fluid thereinto. As a device for insertion of theouter needle, indwelling needles have been known to insert and place theouter needle using the inner needle incorporated inside the outerneedle.

The inner needle is discarded after placement of the outer needle, butit takes a certain time before it is discarded. Therefore, as to anindwelling needle without a safety mechanism, there is a risk of theinner needle, after use, pricking the human body again during thisperiod or a so-called needlestick accident occurring. Since, in thiscase, the inner needle might be contaminated with the HIV virus or thelike, even a needlestick accident alone has been regarded as a cause ofvirus infection.

In order to solve this problem, many types of safety indwelling needleswhich avoid a needlestick accident by confining the inner needleimmediately after use have been developed. For example, a technologydisclosed in Japanese Patent Application Laid-Open Hei 3 No.15481 isdirected to a cannula inserting device for retracting a needle hub,which might cause a needlestick, into a hollow handle by means of anurging means.

Alternatively, Japanese Patent Application Laid-Open No.2000-167051,etc. presented a technology relating to a safety indwelling needle(puncture device) having a retracting mechanism for retracting the innerneedle immediately after use into the holder sleeve. These technologiespresent techniques whereby the inner needle is retracted by means of anurging means when an actuator is operated in a peripheral direction ofthe holder sleeve so that the actuator is fixed to cutout formed in theholder sleeve.

Since the device disclosed in Japanese Patent Application Laid-Open Hei3 No.15481 employs a compression spring as the urging means, the outerand inner needles should be assembled by passing them through theinterior of the compression spring. Hence extra steps are needed inorder for the needle tip not to come into contact with the inner side ofthe compression spring.

With the safety indwelling needle, disclosed in Japanese PatentApplication Laid-Open No.2000-167051, etc., in order to prevent theinner needle once retracted, from being re-exposed, the actuatingelement (actuating portion) needs to be moved in the peripheraldirection so that the actuating element (actuating portion) will befixed to the cutout (engaging window) formed in the holder sleeve (outersleeve) In this case, the following problems will occur. First, thehandedness problem, whereby the actuation is hard to make depending onthe left or right handedness. Further, since one more action needs to bemade to fix the actuating element after retraction of the inner needle(needle portion), this disturbs the quick prevention against re-exposureof the inner needle (needle portion). Thus, there have been someproblems with prevention against re-exposure of the inner needle (needleportion). Further, since the actuating element (actuating portion) isexposed outside the holder sleeve (outer sleeve), there has been a riskof the actuating element (actuating portion) coming away from the cutout(engagement window) due to an external force so as to cause an event ofthe inner needle (needle portion) being exposed.

It is therefore an object of the present applicant to provide atechnology for a safety indwelling needle which is easy to assemble andprevents the inner needle from being re-exposed by an external force.

Particularly, the object of the inventions described in the first tofifth features is to provide a safety indwelling needle which canprevent the inner needle from being re-exposed by an external force.

DISCLOSURE OF INVENTION

In order to attain the above objects, the present invention has thefollowing configurations.

The first feature of the present invention is directed to a safetyindwelling needle, comprised of a metallic inner needle (12) whichpierces the skin of a patient and reaches a blood vessel; and a softouter needle (11) which is located outside the inner needle (12) andplaced within the blood vessel. The safety indwelling needle includes aholder sleeve (1) having a retracting mechanism which can hold the innerneedle (12) after puncture, from the proximal end to the distal endthereof and does not hold the outer needle (11). The retractingmechanism includes: an urging means for urging the inner needle (12) tothe side opposite to the outer needle (11) with respect to the axialdirection of the holder sleeve (1); an actuator (6) which moves togetherwith the inner needle (12) when it is withdrawn and has a punctureposition retainer for keeping the inner needle (12) and outer needle(11) ready for puncture and an inner needle retraction actuating portionfor allowing for the retraction actuation of the inner needle (12); anda slit (2) formed in the holder sleeve (1) for assuring the path ofmovement of the actuator (6). The puncture position retainer has apuncture position engagement portion whereby the actuator (6) is engagedwith the holder sleeve (1) at a position on the outer needle side (11).The inner needle retraction actuating portion includes: an actuatingportion (6 a) for releasing the actuator (6) from the engaged state ofthe puncture position engagement portion into the urged state by theurging means (8) and an actuator housing for enclosing the actuatorafter retraction of the inner needle.

The ‘inner needle (12)’ is usually a metal, mostly made of stainlesssteel. The tip of the inner needle (12) is beveled in order tofacilitate puncture.

The ‘outer needle (11) is placed into the human body after puncture andusually formed of a flexible resin.

The holder sleeve (1) is usually formed of a translucent resin or thelike. When the inner needle (12) is punctured into the human body, theblood passes through the inner needle (12) and reaches the proximalportion (inner needle hub 12 a) of the inner needle (12). Formation ofthese portions with a translucent material allows for confirmation ofthe blood reaching the proximal end of the inner needle (12), hencemakes possible visual recognition that the inner needle (12) has reacheda blood vessel.

With concern to the retracting mechanism, the structure ‘which can holdthe inner needle (12) after puncture and does not hold the outer needle(11)’ can be achieved when, for example, the inner diameter of theholder sleeve is set greater than the proximal end of the inner needle(12) (usually, ‘inner needle hub (12 a)’) and set smaller than theproximal end of the outer needle (11)(usually, ‘outer needle hub (11a)’).

As the ‘urging means’, string-like rubber, etc., may be employed otherthan the coil spring which contracts when no load is applied,

(The Operation of the First Feature)

First, the inner needle (12) and outer needle (11) is kept ready forpuncture by the puncture position engagement portion at which theactuator (6) is engaged with the holder sleeve (1) on the outer needle(11) side. In this position, the inner needle (12) and outer needle (11)are punctured into the skin of a patient.

When the inner needle (12) has reached a blood vessel, the flow of bloodthrough the blood vessel is stopped by one hand while the holder sleeve(1) on the other hand is pulled away from the patient so as to withdrawthe inner needle (12) from the blood vessel. The retracting mechanismwhich can hold the inner needle (12) and does not hold the outer needle(11) is actuated to function as follows.

First, the actuating portion (6 a) is operated so as to release theactuator (6) from the engaged state at the puncture position engagementportion. In response to this, the inner needle (12) is urged to the sideopposite to the outer needle (11) with respect to the axial direction ofthe holder sleeve (1) by the urging means (8), so that the actuator (6)moves along the slit (2), which is followed by the inner needle (12). Onthe contrary, the outer needle (11) will not retract into the holdersleeve (1) but remains at the set position, providing other functionssuch as being connected to an infusion tube.

The inner needle (12) having been moved to the side opposite to theouter needle of the holder sleeve (1) is held from the proximal to thedistal ends, within the holder sleeve (1). Therefore, inner needle (12)having been used for puncture into a patient will not be exposed fromthe holder sleeve (1), whereby it is possible to prevent occurrence ofneedlestick injuries.

Since the actuator (6) moves together with the inner needle (12), therewould be a risk of the inner needle (12) being exposed from the holdersleeve (1) if an external force causing the actuator (6) to move to theouter needle (11) side is applied after retraction of the inner needle(12). However, since the actuator (6) after storage of the inner needle(12) is enclosed by the actuator housing, there is no risk of anexternal force acting on the actuator (6) after retraction of the innerneedle (12). Accordingly, the inner needle (12) will never be exposedfrom the holder sleeve (1) due to this cause.

With concern to ‘urging means’, use of an urging means which contractswhen no load is applied enables easier assembly compared to the casewhere an urging means which extends when no load is applied is usedbecause the inner needle can be assembled without bringing its needletip into contact with the inner side of the compression spring when itis assembled.

‘Actuator housing’ should not be limited to the configuration with wallportions and a protective cover as will be described in the feature ofthe invention, but any configuration will be included in the presentinvention as long as it prevents external force from acting on theactuating element. For example, the portion on the side opposite to theouter needle (11) in holder sleeve (1) may be formed so as to have anaccommodation space for actuator (6) as well.

The second feature of the present invention is the limitation of thesafety indwelling needle written in the first feature, and is directedto a safety indwelling needle wherein the actuator housing portion isconstructed of wall portions (1 b) standing at both sides of the slit(2) in the holder sleeve (1) on the side opposite to the outer needle(11) and a protective cover portion (1 c) joining the edges of the wallportions (1 b).

The ‘wall portions (1 b) and a protective cover portion (1 c)’ may becontinuously formed as a seamless part or may be formed as separateparts.

The wall portions may be formed integrally with the holder sleeve (1) asillustrated for the embodiment, or may be formed by discrete projectionsor the like. It is possible to attain the object of the presentinvention or produce the effect of preventing the inner needle after usefrom being exposed if the wall portions are formed to be higher at acertain point, like the apex of a triangle, than the height of theactuator (6). However, to be more effective, it is preferred that theprojected parts are high enough across the full-length of the actuatingelement.

The protective cover is provided so as to cover the top face of theactuating portion (6 a) projected through the slit (2) of the holdersleeve (1). Also in this case, the top face of the actuating element iscovered, so that it is possible to prevent the inner needle from beingre-exposed when the health care worker's palms and the like touch theactuating portion. Accordingly, the encased state of the inner needlecan be reliably kept within the interior space of the holder sleeve. Asa preferred configuration, the top of the actuating element should becovered when the inner needle is stored in the holder sleeve. Thisconfiguration makes the aforementioned effect possible while minimizingthe amount of material, etc.

(The Operation of the Second Feature)

Since the actuating portion (6 a) after retraction of the inner needle(12) is housed by the walls and protective cover portion, there is noconcern of an external force acting on the actuating portion (6 a) afterretraction of the inner needle (12). Therefore, the inner needle (12)will never be exposed from the holder sleeve (1) due to this cause.

The third feature of the present invention is the limitation of thesafety indwelling needle written in the second feature, and is directedto a safety indwelling needle wherein protective cover portion 1 c isformed so as to function as a tail plug (1 d) for closing the opening ofthe holder sleeve (1) on the side opposite to the outer needle (11).

(The Operation of the Third Feature)

Since protective cover portion 1 c is formed so as to function as a tailplug (1 d) for closing the opening of the holder sleeve (1) on the sideopposite to the outer needle (11), it is possible to reduce the numberof parts and facilitate assembly, hence leading to improvement of theproduction efficiency.

The fourth feature of the present invention is the limitation of thesafety indwelling needle written in any one of the first to thirdfeatures, and is directed to a safety indwelling needle, wherein theretracting mechanism has a stopper for stopping the inner needle (12)when moved to the rear side with respect to the axial direction of theholder sleeve (1), the stopper includes arrest engagements (1 e) forstopping the inner needle (12) stored in the holder sleeve (1) relativeto the holder sleeve (1).

When the function of the stopper is provided by the urging means (8)only, no elements other than the urging means (8) are needed. Though thefunction can be achieved by the urging means (8) only, the engagementarrangement between the holder sleeve (1) and actuator (6) may beprovided subsidiarily. Moreover, since the stopper is to reduce the riskof the health care worker erroneously handling the actuating portion (6a) after retraction of the inner needle (12), the function becomes moresubsidiary when the actuator housing (1 a) is provided.

The arrest engagements, as will be limited by the embodiments describedhereinbelow, may be configured so that inner needle hub (12 a) andholding sleeve (1) will be engaged with each other, other than theconfiguration where the arrest engagements (1 e) are provided at theposition close to the rear end of the slit (2) of the holder sleeve (1)and in the actuating portion (6 a).

(The Operation of the Fourth Feature)

The stopper stops the motion of the inner needle (12) having been movedto the side of holder sleeve (1) opposite to the outer needle, byengagement between arrest engagements (1 e) for stopping the innerneedle (12) held in the holder sleeve (1) relative to the holder sleeve(1). Therefore, there is little risk of the inner needle (12), oncemoved to the side of holder sleeve (1) opposite to the outer needle,being re-exposed due to an erroneous operation, and the like.

The fifth feature of the present invention is the limitation of thesafety indwelling needle written in any one of the first to fourthfeatures, and is directed to a safety indwelling needle, wherein, on theouter needle (11) side of the holder sleeve (1), a grip portion (1 g) tobe held when the outer needle (11) and inner needle (12) are puncturedinto the skin of a patient is formed at a position other than theposition where the actuating portion (6 a) of the actuator (6) isarranged.

(The Operation of the Fifth Feature)

Since the grip portion (1 g) is formed at a position other than theposition where the actuating portion (6 a) of the actuator (6) isarranged, it is possible to reduce the risk of the actuating portion (6a) being erroneously handled when the outer needle (11) and inner needle(12) are punctured into the skin of a patient.

The sixth feature of the present invention is the limitation of thesafety indwelling needle written in any one of the first to fifthfeatures, and is directed to a safety indwelling needle furthercomprising a cap 20 which covers the outer needle (11) and inner needle(12) while keeping them ready for puncture and disables the function ofthe actuating portion (6 a).

(The Operation of the Sixth Feature)

Cap (20) is covered in the state where the outer needle (11) and innerneedle (12) are kept ready for puncture. Therefore, the device can beused immediately when the cap (20) is removed just before the use for apatient.

Since the actuating portion (6 a) is made disabled when the cap (20) isfitted, it is possible to prevent erroneous operations such as causingwithdrawal of inner needle (12) into holder sleeve (1).

The seventh feature of the present invention is also directed to asafety indwelling needle, comprised of a metallic inner needle (12)which pierces the skin of a patient and reaches a blood vessel; and asoft outer needle (11) which is located outside the inner needle (12)and placed within the blood vessel.

First, this safety indwelling needle includes: a holder sleeve (1)having a retracting mechanism which can hold the inner needle (12) afterpuncture, from the proximal to distal ends thereof and does not hold theouter needle (11). The retracting mechanism includes: a coil spring (8)for urging the inner needle (12) to the side opposite to the outerneedle (11) with respect to the axial direction of the holder sleeve(1); an actuator (6) which is arranged between the coil spring (8) andthe inner needle (12), moves together with the inner needle (12) when itis withdrawn and has a puncture position retainer for keeping the innerneedle (12) and outer needle (11) ready for puncture and an inner needleretraction actuating portion for allowing for the withdrawal actuationof the inner needle (12); and a slit (2) formed in the holder sleeve (1)for assuring the movement path of the actuator (6); an actuator housingfor enclosing the actuator (6) after retraction of the inner needle(12); and a stopper for stopping the inner needle (12), having beenmoved to the side opposite to the outer needle of the holder sleeve (1).

The puncture position retainer has a puncture position engagementportion whereby the actuator (6) is engaged with the holder sleeve (1)at a position on the outer needle (11) side and the engagement can bereleased.

The inner needle retraction actuating portion includes: an actuatingportion (6 a) for releasing the actuator (6) from the engaged state ofthe puncture position engagement portion into the urged state by thecoil spring (8).

The actuator housing portion is constructed of wall portions (1 b)standing at both sides of the slit (2) in the holder sleeve (1) on theside opposite to the outer needle and a protective cover portion (1 c)joining the edges of the wall portions (1 b), the protective coverportion (1 c) being formed so as to function as a tail plug (1 d) forclosing the opening of the holder sleeve (1) on the side opposite to theouter needle (11).

The stopper includes arrest engagements (1 e) for stopping the innerneedle (12) held in the holder sleeve (1) relative to the holder sleeve(1).

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an overall perspective view showing an example of a safetyindwelling needle of the present invention;

FIG. 2 is a partially sectional vertical view showing a safetyindwelling needle before use, according to the present invention;

FIG. 3 is a partly enlarged, partially sectional vertical view showing aconfigurational example of an actuator housing and thereabout when theinner needle is retracted into a holder sleeve;

FIG. 4 is a partly enlarged, partially sectional vertical view showingthe actuating portion and thereabout shown in FIG. 1;

FIG. 5 is a partially sectional vertical view showing a safetyindwelling needle when the inner needle is retracted into the holdersleeve;

FIG. 6 is an enlarged, partially sectional view showing an actuatingportion and thereabout according to the first embodiment;

FIG. 7 is an overall perspective view showing an example of a safetyindwelling needle with a cap fitted thereto;

FIG. 8 is a perspective view showing a cap viewed from the opening side;

FIG. 9 is a perspective view showing the second embodiment;

FIG. 10 is a partially exploded perspective view showing the secondembodiment;

FIG. 11 a partially sectional view showing the second embodiment;

FIG. 12 a partially sectional view showing the second embodiment;

FIG. 13 is a partially sectional view showing a state where the innerneedle is held in the second embodiment;

FIG. 14 is a perspective view showing a state where inner and outerneedles are assembled;

FIG. 15 is a perspective view showing the third embodiment;

FIG. 16 is a partially sectional enlarged view showing an actuatingportion and thereabout according to the third embodiment;

FIG. 17 is a partially sectional enlarged view showing an actuatingportion and thereabout according to the third embodiment;

FIG. 18 is a partially sectional enlarged view showing an actuatingportion and thereabout according to the fourth embodiment; and

FIG. 19 is a partially sectional enlarged view showing an actuatingportion and thereabout according to the fourth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

(The First Embodiment)

The first embodiment will be described with reference to FIGS. 1 through8.

FIG. 1 shows a safety indwelling needle comprised of a metallic innerneedle 12 which penetrates the skin of a patient and reaches a bloodvessel and a soft outer needle 11 which is located outside the innerneedle 12 and is to be placed within the blood vessel. This safetyindwelling needle includes a holder sleeve 1 having a retractingmechanism which can hold the inner needle 12 after puncture, from theproximal to distal ends thereof and does not hold outer needle 11. Thisretracting mechanism is comprised of an urging means 8 for urging innerneedle 12 to the side opposite to outer needle 11 with respect to theaxial direction of holder sleeve 1, an actuator 6 located between urgingmeans 8 and inner needle 12 and fixed to urging means 8 and an innerneedle hub 12 a, a slit 2 formed in holder sleeve 1 for assuring thepath of movement of the actuator 6 and a stopper for arresting innerneedle 12 which have been moved to the axially rear side of holdersleeve 1 (the side opposite to the outer needle).

As urging means 8, a coil spring which contracts when no load is appliedis employed. Use of an urging means which contracts when no load isapplied enables easier assembly compared to the case where an urgingmeans which extends when no load is applied is used because the needletip of the inner needle can be kept out of contact with the inner sideof the compression spring when it is assembled.

In order to facilitate connection of an outer needle hub 11 a with atube for medical liquids, the outer needle hub is funnel-shaped having aflange 11 b at its rear end. As shown in FIG. 6, a filter 13 is attachedinside inner needle hub 12 a in order for the patient's blood not toleak out.

Holder sleeve 1 is comprised of an actuator housing 1 a for protectingan actuating portion 6 a of actuator 6 when inner needle 12 has beenretracted in holder sleeve 1, a cutout portion. If formed at the sidethereof close to outer needle 11, holding portions 1 g to enable thesafety indwelling needle body to be held with the first and third digitswhen inner needle 12 and outer needle 11 are punctured into the patient.Cutout portion if is formed so that the second digit can touch innerneedle hub 12 a, in order to facilitate operation when inner needle 12and outer needle 11 are punctured into a patient.

The aforementioned actuator housing 1 a is placed the side opposite toouter needle 11 on holder sleeve 1 and is constructed by a pair of wallportions 1 b intervening slit 2 between them formed continuously fromholder sleeve 1 and a protective cover portion 1 c bridging between thewall portions 1 b. The wall portion 1 b is formed with a curved outlineso as to visually suppress the projective appearance of the housing ofactuator 6.

Protective cover portion 1 c is formed separately from holder sleeve 1and is formed together with a tail plug 1 d which closes the opening ofholder sleeve 1 on the side opposite to outer needle 11 and fixes oneend of coil spring 8 thereto. Since protective cover portion 1 c isformed with tail plug 1 d for closing the opening of holder sleeve 1 onthe side opposite to outer needle 11, it is possible to reduce thenumber of parts and facilitate assembly, hence also improve theproduction efficiency. Fixture of protective cover portion 1 c to holdersleeve 1 may be performed by press-fitting, heat-bonding, bonding usingadhesives or the like.

Further, protective cover portion 1 c has an arrest engagement 1 etherein for holding inner needle 12 at the rear end of holder sleeve 1when the needle has been retracted within holder sleeve 1.

Actuator 6 moves together with inner needle 12 when the needle isretracted and has the following configuration in order to keep inner andouter needles 12 and 11 ready for puncture. First, actuator 6 iscomprised of actuating portion 6 a projected outward of holder sleeve 1through slit 2, an insert projection 6 b which is inserted to anengagement window 3 formed in holder sleeve 1 on the side close to outerneedle 11 to keep actuator 6 to the side close to outer needle 11opposing the urging force of urging means 8, a lifting portion 6 d towhich the finger is applied when the insert projection 6 b is raisedfrom engagement window 3, an actuating support 6 c serving as a fulcrumfor the lifting portion 6 d and an arrest engagement 1 e for holdinginner needle 12 at the rear end of holder sleeve 1 when the needle hasbeen retracted within holder sleeve 1. Insert projection 6 b andengagement window 3 are formed at such positions that the path ofmovement of actuating portion 6 a is included within the same plane thatincludes the axis of holder sleeve 1.

When the holding portions 1 g, arranged at the front part of holdersleeve 1 on both sides of engagement window 3, are held horizontally bythe first and third digits with the second digit set perpendicularly ata position slightly forward with respect to the first and third digits,the rear end of holder sleeve 1 abuts the palm, so that the needle tipcan be fixedly held. In this position, inner needle 12 and outer needle11 are punctured into the vein or any other blood vessel of the humanbody, then the flange 11 b and thereabout at the rear end of outerneedle hub 11 a is pushed out by the second digit so as to place theouter needle 11 into the blood vessel. Since cutout if is formed at thefront most end of holder sleeve 1, flange 11 b and thereabout areadapted to be easily pushed out.

Since inner needle 12 is unsheathed after outer needle 11 has beenplaced into the patient, lifting portion 6 d at the front part ofactuating portion 6 a is lifted upward so as to release the inner needlefrom the engagement. At this moment, the path of movement of liftingportion 6 d is not a rotational motion direction about axis of holdersleeve 1, so no handedness problem will occur. As pulled by coil spring8 fixed between tail plug 1 d and actuator 6, actuator 6 is movedbackwards into holder sleeve 1. Since inner needle 12 is fixed toactuator 6 via inner needle hub 12 a, inner needle 12 is also pulledinto holder sleeve 1. In this way, inner needle 12 is kept away from theoutside, thus enabling safe disposal.

As shown in FIG. 3, actuating portion 6 a projected from holder sleeve 1is covered over its top face 6 e by a protective cover 1 c and enclosedby walls 1 b formed continuously from holder sleeve 1 on both sides ofactuating portion 6 a. Each of these elements is kept away at a largeenough clearance from actuating portion 6 a so that there is little riskof actuating portion 6 a being externally pressed by the palm or thelike of the health care worker.

Triangular arrest engagements 1 e are formed on actuating portion 6 aand at around the rear end of slit 2, respectively. The arrestengagement 1 e formed at the rear of actuating portion 6 a which hasbeen moved by the urging force of coil spring 8 will readily pass overthe arrest engagement 1 e of holder sleeve 1. Since two arrestengagements 1 e have interlocking shapes with each other or since theopposing sides of the triangles of actuating portion 6 a and holdersleeve 1 are right-angled to the respective portions, the movement ofactuator 6 toward the side of outer needle 11 is restrained. As aresult, the forward movement of inner needle 12 is also restrained.

FIG. 4 shows a state before puncture into a patient. Before inner andouter needles 12 and 11 are punctured into a blood vessel, insertprojection 6 b of actuating portion 6 a has been set in engagementwindow 3 of holder sleeve 1. This opposes the urging force of coilspring 8 which tends to urge inner needle 12 into holder sleeve 1.

In order to retract inner needle 12 into holder sleeve 1 after outerneedle 11 has been placed into the human body, the lifting portion 6 dof actuating portion 6 a is pulled upwards. Then actuating portion 6 arises at the front end, pivoting on actuating support 6 c, so thatinsert projection 6 b which has been fitted in engagement window 3 ispulled out. Resultantly, inner needle 12 together with actuator 6 isretracted into holder sleeve 1 by the urging force of coil spring 8.

FIG. 5 shows the fact that the actuating element 6 is difficult to beinterfered with from an external since the height h2 of wall portions 1b is greater than the height h1 of actuating element 6. In the presentembodiment, h1 and h2 are set at about 7.3 mm and 9.7 mm, respectively.

FIG. 7 shows a state where a cap 20 is fitted. FIG. 8 is a perspectiveview of cap 20 viewed from the opening side. Cap 20 covers outer andinner needles 11 and 12 in such a manner that they are ready forpuncture and has an actuation stopper groove 20 a in which actuatingportion 6 a is fitted in an immovable manner in order to make actuatingportion 6 a disabled. Hence, since actuating portion 6 a is madedisabled as long as cap 20 is fitted, it is possible to prevent innerneedle 12 from being retracted into holder sleeve 1 as well aspreventing other mal-operations.

The present invention will be described with reference to anotherembodiment with its drawings.

The relationship between inner needle 12 and outer needle 11 is as shownin FIG. 14. As stated already, an outer needle structure 10 has outerneedle 11 as a soft-resin made pipe needle. This outer needle 11 has athin-walled pointed part producing an increased contact with innerneedle 12. Provided at the side opposite to the pointed part is afunnel-shaped outer needle hub 11 a for connection with a tube of amedical fluid such as for infusion.

Holder sleeve 1 has a slit 2 formed for assuring the path of movement ofan actuator 6 when the retracting mechanism is actuated.

As shown in FIGS. 9 and 11, actuating portion 6 a is extended fromactuator 6 outwardly beyond the holder sleeve through slit 2 while thefront part of actuating portion 6 a is fitted into an engagement window3 which is formed close to slit 2 in the front part of holder sleeve 1.This actuating portion 6 a is also extended to the rear. When part ofthis actuating portion 6 a extended to the rear is pressed, theinsertion of the actuating portion into engagement window 3 isdisengaged by the lever principle to reach the separated position. Theactuating element has anti-slip ribs 14 at its rear part.

When inner and outer needles 12 and 11 are used to puncture, actuatingportion 6 a is positioned at the fitted position or fixed position 4(FIG. 11) where the front part of actuating portion 6 a is fitted in theengagement window 3 of holder sleeve 1. Therefore, outer and innerneedles 11 and 12 are kept projected from the holder sleeve 1.

FIG. 13 shows the state of inner needle 11 and actuator 6 immediatelyafter retraction. When the rear part of actuating portion 6 a is pressedin the radial direction of holder sleeve 1, the front end of actuatingportion 6 a moves in the direction opposite to the pressed direction.Pressing the rear part of actuating portion 6 a in the radial directionmakes the front part of actuating portion 6 a move to the position wherethe engaged state is released or a separated position 5 (FIG. 12). Atthe same time, the urging means urges inner needle 12 toward the rearend of holder sleeve 1 in direction of its axis, whereby actuator 6smoothly and quickly moves to the rear side along the inner wall of theholder sleeve. In this way, inner needle 12 moves into the interiorspace of holder sleeve 1 and is stored therein as shown in FIG. 13.

With concern to the method of assembly of the safety indwelling needleof the present invention, actuator 6, coil spring 8 and tail plug 9 areinserted into holder sleeve 1 from its rear end. Actuator 6 is moved tothe front of the holder sleeve with actuating portion 6 a fitted throughslit 2 until actuating portion 6 a is inserted into engagement window 3.After the insertion, outer and inner needles 11 and 12 are attached toactuator 6 from the front side of the holder sleeve.

By adopting this method, assembly can be done without the needle tipbeing interfered since inner and outer needles 12 and 11 are not passedthrough either coil spring 8 or the holder sleeve. In view of improvingthe efficiency for fitting actuator 6, coil spring 8 and tail plug 9from the rear end of holder sleeve 1, it is preferred that these threeparts have been assembled in advance.

FIGS. 15 to 17 show a safety indwelling needle of the third embodiment.Actuating portion 6 a shown in FIG. 15 is projected from actuator 6through slit 2 and extended forwards only with part of it fitted inengagement window 3 of holder sleeve 1, as shown in FIG. 16. Anti-slipribs 14 are formed on the front side surface of actuating portion 6 a.

FIG. 17 shows the released state where the insertion of actuatingportion 6 a is disengaged. Shift of actuating portion 6 a from itsinserted state to released state is made by lifting the front part ofactuating portion 6 a where anti-slip ribs 14 are formed.

Even if the fingers of the health care worker or certain items presentaround the health care worker abut actuating portion 6 a when inner andouter needles 12 and 11 is used to puncture, the moment of the force dueto the abutment is opposite to the moment of a force for releasing theinserted state. Therefore, the moments of the force about the fulcrum atthe joint 15 between the actuating element and the actuator act in theopposite direction mutually, so that the inserted state will not bereleased by an erroneous operation. The method of assembly and otherconfigurations are the same as those shown in the embodiment describedabove.

Though this reference is common to other embodiments, it is preferredthat actuator 6 and actuating portion 6 a should be formed of a materialhaving elasticity. This feature makes actuating portion 6 a displaceeasily hence release easily from the inserted state. It is also possibleto connect actuating portion 6 a and actuator 6 with another element orconfigure part of actuating portion 6 a to be fitted into engagementwindow 3, by a separate part.

FIGS. 18 and 19 show the fourth embodiment of actuating portion 6 a.FIG. 18 shows a state where the front part of actuating portion 6 a fitsinto engagement window 3. In this state inner and outer needles 12 and11 are used to puncture. FIG. 19 shows a state where the inserted stateis disengaged. The inserted state is released by pressing actuatingportion 6 a from the holder sleeve side so as to lift actuating portion6 a. In this embodiment, other configurations are the same as thoseshown in the first embodiment.

In any of the above embodiments, an anti-slip portion such as anti-slipribs 14 or a projection to be held by the finger may be formed on theactuating element in order to facilitate the actuating element to behandled.

It should be noted that the engaged state in the puncture positionengagement portion can be disengaged by moving part of the actuatingportion away from the holder sleeve. It is preferred that the path ofmovement of the actuating portion is included in the same plane thatincludes the axis of the holder sleeve.

Examples of the structures for releasing the engaged state by shiftingpart of the actuating portion away from the holder sleeve include astructure for directly lifting actuating portion 6 a so as to move theengaging part away from the holder sleeve 1 side, and a structure inwhich, though actuating portion 6 a is pressed toward holder sleeve 1,the engaging portion is lifted up by providing a pivot. As part ofactuating portion 6 a is moved away from holder sleeve 1, the engagedstate of the puncture position engagement portion is released, wherebyinner needle 12 is withdrawn into holder sleeve 1. This action,differing from a depressing action, almost never causes an erroneousactuation. Since the movement path of actuation is included within thesame plane that includes the axis of holder sleeve 1, it is possible toprovide a user-friendly safety indwelling needle, whether the user isleft-handed or right-handed.

Also, the puncture position engagement portion of the safety indwellingneedle may be constructed of an engagement window formed in the frontpart of the holder sleeve and an insert projection formed in theactuating portion, wherein the insert projection is fitted in theengagement window when in the puncture position and the engaged statecan be released by moving the insert projection away from the holdersleeve. Also in this case, the action, differing from an depressingaction, almost never causes an erroneous actuation. Further, also inthis case, the movement path of actuation is included within the sameplane that includes the axis of holder sleeve 1, it is possible toprovide a user-friendly safety indwelling needle, whether the user isleft-handed or right-handed.

Alternatively, the puncture position engagement portion of the safetyindwelling needle may be formed of an engagement window formed in thefront part of the holder sleeve and an insert projection formed in theactuating portion and constructed such that the insert projection isfitted in the engagement window when in the puncture position while theactuating portion is joined to the actuator at a position behind theinsert projection, by an actuation support and the engaged state can bereleased by moving the insert projection away from the holder sleeve, bylifting the front part of the actuating portion.

In this case, the arrangement of the actuation support as the jointbetween the actuating portion and the actuator at a position behind theinsert projection facilitates smooth actuation. Illustratively, when theinner needle is placed into the human body, the inner needle needs to bepushed out by the second digit. Hence, the second digit will be locatedaround the cutout portion of the holder sleeve after the placement ofthe inner needle. Then, the withdrawal of the inner needle shouldfollow. Since the actuating portion is joined to the actuator by theactuation support at a position behind the insert projection, the frontpart of the actuating portion should be pulled up in order to lift theinsert projection. Therefore, the second digit is located around thecutout portion or in front of the actuating portion as mentioned above,this makes it possible to raise the front part of the actuating portionimmediately, hence quickly begin to withdraw the inner needle. Further,a lifting portion which is touched by the finger when the insertprojection is lifted from the engagement window may be formed at thefront part of the actuating portion.

If no lift portion for raising the actuating portion is equipped, thismakes quick withdrawal of the inner needle difficult. This is why alifting portion is provided at the front part of the actuating portionin the present invention, whereby a quicker and more reliable retractionof the inner needle can be made possible.

It is preferred that the lifting portion is formed on the surface facingto the front as is shown in FIG. 6. It is also preferred that the anglea between the axis and the lifting portion is set at 90 degrees orsmaller because this makes it possible for the lifting portion to hookthe finger reliably. Moreover, it is preferred that anti-slip such asserration is formed because this also enables quick reliable withdrawalof the inner needle.

The safety indwelling needle of the present application is aimed atproviding a technology which allows for easy assembly and preventionagainst re-exposure of the inner needle due to an external force.

In particular, a further object of the inventions written in the firstto fifth aspects is to provide a safety indwelling needle which is ableto prevent re-exposure of the inner needle due to an external force.

INDUSTRIAL APPLICABILITY

The safety indwelling needle according to the present invention is asafety indwelling needle comprised of a soft outer needle to be placedin a blood vessel and a hard inner needle which is fitted in the outerneedle to pierce through the skin of a patient so as to insert the outerneedle into a blood vessel, and provides a suitable configuration whichprevents occurrence of erroneous operations before and during usage, isnot different in handling depending on the handedness, allows for easyassembly and prevents re-exposure of the inner needle.

1. A safety indwelling needle, comprised of a metallic inner needlewhich pierces a skin of a patient and reaches a blood vessel; and a softouter needle which is located outside the inner needle and places withinthe blood vessel, comprising: a holder sleeve having a retractingmechanism which can hold the inner needle after a puncture, from aproximal end to a distal end thereof and does not hold the outer needle,characterized in that the retracting mechanism includes: an urging meansfor urging the inner needle to a side opposite to the outer needle withrespect to an axial direction of the holder sleeve; an actuator whichmoves together with the inner needle when it is withdrawn and has apuncture position retainer for keeping the inner and outer needles readyfor the puncture and an inner needle retraction actuating portion forallowing for the retraction actuation of the inner needle; and a slitformed in the holder sleeve for assuring a movement path of theactuator, the urging means is a biasing element that applies a biasingforce to the actuator, the inner needle retraction actuating portion ispositioned at an outside of the holder sleeve through the slit when theinner and outer needles are readied for the puncture, the punctureposition retainer has a puncture position engagement portion whereby theactuator is engaged with the holder sleeve at a position on an outerneedle side, the inner needle retraction actuating portion has anactuating portion for releasing the actuator from an engaged state ofthe puncture position engagement portion into an urged state by theurging means, and the retracting mechanism has an actuating portionhousing for enclosing the inner needle retraction actuating portion whenthe inner needle retraction actuating portion biasedly retracts withinand underneath a protective cover portion of the actuating portionhousing to prevent both ends of the actuator from being freelyaccessible resulting in the actuating portion housing preventing theinner needle retraction actuating portion from coming into contact witha hand after retraction of the inner needle.
 2. The safety indwellingneedle according to claim 1, wherein the actuator housing portion isconstructed of wall portions formed standing at both sides of the slitin the holder sleeve on the side opposite to the outer needle and theprotective cover portion joining the edges of the wall portions.
 3. Thesafety indwelling needle according to claim 2, wherein the protectivecover portion is formed so as to function as a tail plug for closing anopening of the holder sleeve on the side opposite to the outer needle.4. The safety indwelling needle according to claim 1, wherein theretracting mechanism has a stopper for arresting the inner needle movedto the side of the holder sleeve opposite to the outer needle, thestopper includes arrest engagements for stopping the inner needle storedin the holder sleeve relative to the holder sleeve.
 5. The safetyindwelling needle according to claim 1, wherein, on the outer needleside of the holder sleeve, a grip portion to be held when the outer andinner needles are punctured into the skin of the patient is formed at aposition other than a position where the actuating portion of theactuator is arranged.
 6. The safety indwelling needle according to claim1, further comprising a cap which covers the outer and inner needleswhile keeping them ready for puncture and disables the function of theactuating portion.
 7. A safety indwelling needle, comprised of ametallic inner needle which pierces a skin of a patient and reaches ablood vessel; and a soft outer needle which is located outside the innerneedle and placed within the blood vessel, comprising: a holder sleevehaving a retracting mechanism which can hold the inner needle after apuncture, from a proximal end to a distal end thereof and does not holdthe outer needle, characterized in that the retracting mechanismincludes: a coil spring for urging the inner needle to a side oppositeto the outer needle with respect to an axial direction of the holdersleeve; an actuator which is arranged between the coil spring and theinner needle, moves together with the inner needle when it is withdrawnand has a puncture position retainer for keeping the inner and outerneedles ready for the puncture and an inner needle retraction actuatingportion for allowing a withdrawal actuation of the inner needle; a slitformed in the holder sleeve for assuring a movement path of theactuator; an actuating portion housing for enclosing the inner needleretraction actuating portion when the inner needle retraction actuatingportion biasedly retracts within and underneath a protective coverportion of the actuating portion housing to prevent both ends of theactuator from being freely accessible resulting in the actuating portionhousing preventing the inner needle retraction actuating portion fromcoming into contact with a hand after retraction of the inner needle;and a stopper for stopping the inner needle, having been moved to a rearside with respect to the axial direction of the holder sleeve, the innerneedle retraction actuating portion is positioned at an outside of theholder sleeve through the slit when the inner and outer needles arereadied for the puncture, the puncture position retainer has a punctureposition engagement portion whereby the actuator is engaged with theholder sleeve at a position on an outer needle side and an engaged statecan be released, the inner needle retraction actuating portion includes:an actuating portion for releasing the actuator from the engaged stateof the puncture position engagement portion into an urged state by thecoil spring, the actuator housing portion is constructed of wallportions standing at both sides of the slit in the holder sleeve on theside opposite to the outer needle and a protective cover portion joiningthe edges of the wall portions, the protective cover portion beingformed so as to function as a tail plug for closing an opening of theholder sleeve on the side opposite to the outer needle, and the stopperincludes arrest engagements for stopping the inner needle held in theholder sleeve relative to the holder sleeve.
 8. The safety indwellingneedle according to claim 1, wherein the puncture position retainer isprojected outward of holder sleeve through the slit, and the punctureposition engagement portion is engaged with an engagement windowprovided on an outer surface of the holder sleeve.
 9. The safetyindwelling needle according to claim 7, wherein the puncture positionretainer is projected outward of holder sleeve through the slit, and thepuncture position engagement portion is engaged with an engagementwindow provided on an outer surface of the holder sleeve.
 10. The safetyindwelling needle according to claim 1, wherein the biasing element isin a compressed state when the inner needle is retracted.
 11. The safetyindwelling needle according to claim 7, wherein the coil spring is in acompressed state when the inner needle is retracted.
 12. The safetyindwelling needle according to claim 1, wherein the protective coverportion has a length that is greater than the length of the inner needleretraction actuating portion such that a free end of the protectivecover portion extends beyond the inner needle retraction actuatingportion so as to completely cover the inner needle retraction actuatingportion.
 13. The safety indwelling needle according to claim 1, whereinthe housing is constructed such that lateral access to and access to theinner needle retraction actuating portion from above are prevented. 14.The safety indwelling needle according to claim 1, wherein theprotective cover portion extends above and across a length of an outersurface of the holder sleeve.
 15. A safety indwelling needle, comprisedof a metallic inner needle which pierces a skin of a patient and reachesa blood vessel; and a soft outer needle which is located outside theinner needle and places within the blood vessel, comprising: a holdersleeve having a retracting mechanism which can hold the inner needleafter a puncture, from a proximal end to a distal end thereof and doesnot hold the outer needle, characterized in that the retractingmechanism includes: an urging means for urging the inner needle to aside opposite to the outer needle with respect to an axial direction ofthe holder sleeve; an actuator which moves together with the innerneedle when it is withdrawn and has a puncture position retainer forkeeping the inner and outer needles ready for the puncture and an innerneedle retraction actuating portion for allowing for the retractionactuation of the inner needle; and a slit formed in the holder sleevefor assuring a movement path of the actuator, the urging means is abiasing element that applies a biasing force to the actuator, the innerneedle retraction actuating portion is positioned at an outside of theholder sleeve through the slit when the inner and outer needles arereadied for the puncture, the puncture position retainer has a punctureposition engagement portion whereby the actuator is engaged with theholder sleeve at a position on an outer needle side, the inner needleretraction actuating portion has an actuating portion for releasing theactuator from an engaged state of the puncture position engagementportion into an urged state by the urging means, and the retractingmechanism has an actuating portion housing that includes a structurethat extends the length of the inner needle retraction actuating portionwhen the inner needle retraction actuating portion retracts within theactuating portion housing such that a free end of the structure extendsbeyond the inner needle retraction actuating portion so as to completelycover the inner needle retraction actuating portion, thereby preventingthe inner needle retraction actuating portion from coming into contactwith a hand after retraction of the inner needle.